-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 6/13/2012 8:42 PM, Scott Hasse wrote: > 1) Many of the output pins are step/dir which of course will > require real time control, but others things like heater outputs, > etc, that would not suffer too much from increased latency. Has > anyone used a latching shift register for extending parallel port > output for cases where latency is less of a concern?
I'm not aware of anything specifically like this. The Mesa folks (and others) use the parallel port in EPP mode and get something like what you're talking about. I've considered taking the AVR and using it as a "poor-man's" Mesa, but I'm not sure it's going to be worth the hassle. It would provide a fairly easy way to expand the I/O, and get full support for multiple analog channels via the A/D. > 2) I've gotten some basic encoder-based frequency-based analog > input working in other scenarios ( > http://code.google.com/p/sector67-sandbox/wiki/FrequencyBasedAnalogInput) > > and plan to use that for the analog temperature inputs on the parallel port > if feasible. Does that seem reasonable? It seems perfectly reasonable. I am planning on just using something like a 555 timer to convert the thermistor resistance into a frequency that can be sampled by the HAL parallel port or (if I need more resolution) using the analog audio input and something like aubiopitch. > 3) Has anyone else done anything similar to this? I've followed > the http://reprap.org/wiki/EMCRepRap effort, but that doesn't use > the RAMPS board. I expect the user interface and gcode translation > tools from that project to be quite useful. I think I'm heading down pretty much exactly the same path you are, although I've been recently side-tracked actually trying to assemble my MendelMax 3D printer. I picked up some proto-shield boards cheap off eBay (see item 280871493314), which I plan on using to replace the Arduino by tying directly to the parallel port. ...but first I have to finish the 3D printer, which is *ALMOST* done. *wanders off to work on the wiring harness* - -- Charles Steinkuehler char...@steinkuehler.net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk/ZUnIACgkQLywbqEHdNFyRbwCfUjoLP5gmLoDpEqMaZUktYzDl kmIAoKm+tJ3GPZ4ykiqrw1X+2434A+Yu =LPqO -----END PGP SIGNATURE----- ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
